condition mean min max ZT0-3 2.46812 1.74066 3.2599349999999996 ZT4-7 1.3869 1.3869 1.3869 ZT8-11 1.149915 1.149915 1.149915 ZT12-15 1.44072525 1.1586855 1.722765 ZT16-19 1.9270800000000001 1.9270800000000001 1.9270800000000001 ZT20-23 2.76733 2.76733 2.76733